Mechanism for preparing and presenting single thread lengths to a weft device of a weaving loom

ABSTRACT

A pneumatic thread preparing and presenting mechanism which is suitable for handling low twisted yarns in that the thread in its path from the storage cone to the weaving shed is exposed to relatively low tensions.

United States Patent Vermeulen et a]. 14 1 July 11, 1972 [54] MECHANISMFOR PREPARING AND 58 Fleld olSearch ..139/122 R, 127 P; 66/125PRESENTING SINGLE THREAD LENGTHS TO A WEFT DEVICE OF A [56] Ram CMWEAVING LOOM FOREIGN PATENTS 0R APPLICATIONS I 1 lnvemom Jan Antonius6,616,526 5/1968 Netherlands ..139/121 P both of Deume, Netherlands461,401 8/! 968 Switzerland ..139/121 P [73] Assignee: v M'chhdabflek L.m strike 477,58l 8/]969 Switzerland 139/127 P Deurne, NetherlandsPrimary Examiner-Henry S. Jaudon Filed: Attorney-Marshall & Yeasting l.N "8,043 [211 App 51 ABSTRACT [30] Foreign u u Prim-"y m A pneumaticthread preparing and presenting mechanism which is suitable for handlinglow twisted yarns in that the March 30, I971 Netherlands ..7003045thread in its path f a storage cone to the weaving shed is exposed torelatively low tensions. 52 us. c1 ..139 127 P [51 1 Int. Cl. ..D03d47/34 2 Claims, 4 Drawing Figures MECHANISM FOR PREPARING AND PRESENTINGSINGLE THREAD LENGTI-IS TO A WEFI DEVICE OF A WEAVING LOOM BACKGROUND OFTHE INVENTION The invention aims at providing a simplified mechanism forpreparing and presenting measured single thread lengths to a weft deviceof a weaving loom, said mechanism being particularly suitable to beapplied in weaving looms adapted for weaving with a false selvage suchas occurs when weaving with various kinds of synthetic yarns.

More particularly the invention aims at providing a pneumatic threadpreparing and presenting mechanism which is suitable for handling lowtwisted yarns in that the thread in its path from the storage cone tothe weaving shed is exposed to relatively low tensions, as compared withthe known mechanisms, and in general is spared in greater measure.

Various constructions of mechanisms serving for the preparation andpresentation to a weft device of a weaving loom of measured threadlengths are already known. Said mechanisms, which mostly are adapted tothe preparation of double thread lengths and to weaving with selvage,are relatively complicated in view of the many moving parts, theapplication of inserting needles and the special provisions connectedwith the launching of double thread lengths in two pieces of unequallength.

SUMMARY OF THE INVENTION The mechanism proposed by the invention ischaracterized by a first auxiliary nozzle which follows a thread feedingdevice, said nozzle having its exit opening directed to a first storingshaft for permitting a first thread loop to be received in said storingshaft, the leading run of said loop extending via a first thread clampthrough a second auxiliary nozzle, the exit opening thereof beingsituated opposite to a second storing shaft for the reception into thesaid shaft of a second thread loop, the leading run of which extends tothe main nozzle of the weft device, a second thread clamp as well as acutting device being provided adjacent to the main nozzle. The threadclamps as well as the cutting device are controlled so that during theone half of a weaving cycle the first thread clamp is closed, the secondthread clamp is open and the cutting device is inoperative a thread looppreviously formed in the second storing shaft being inserted into theweaving shed by the main nozzle and a new" thread loop being at the sametime inserted into the first storing shaft by the first auxiliary nozzlewhereas in the other half of the same weaving cycle the first threadclamp is opened and the second thread clamp is closed, the thread loopformed during the previous half cycle in the first storing shaft beingtransmitted by the second auxiliary nozzle to the second storing shaft,whereas the cutting device is actuated at the transition from the firstto the second half of the weaving cycle for cutting off the threadlength inserted into the weaving shed by the main nozzle.

Preferably the nozzles are controlled so that the first auxiliary nozzleis actuated continuously, the second auxiliary nozzle only during thesecond half of the weaving cycle and the main nozzle only during thefirst half of the weaving cycle.

BRIEF DESCRIPTION OF THE DRAINING FIG. 1 is a diagrammatic view inperspective of a mechanism embodying the invention,

FIG. 2 is a fragmentary elevation of a conventional device forcontrolling the supply of air to a nozzle.

FIG. 3 is a fragmentary elevation of a conventional device for operatinga thread clamp.

FIG. 4 is a fragmentary elevation of a conventional thread cuttingdevice.

In the mechanism shown in the drawing, which mechanism is adapted to bemounted alongside a weaving machine, the weft thread 1 is drawn directlyfrom a storage cone 2 and supplied via a pneumatically operating supplyand breaking device 3, controlling the tension of the thread, to a setof measuring rolls 4a, 4b. The pneumatic supply and breaking device 3 isfor instance constructed as described in the Dutch patent application66l0l74, laid open for public inspection. From the measuring rolls 4a,4b, the larger one 40 of which may be driven at a speed that isadjustable in correspondence with the width of the cloth to be woven,the thread is taken by a first auxiliary noule S of a known type whichpermits the thread to be received in the shape of a loop 6 into thestoring shaft 7. If necessary the end 7' of the shaft 7 may also beconnected to a suction device. The thread further moves via a firstthread clamp 8 through a second auxiliary noule 9, which last mentionedauxiliary nozzle may likewise be of a known type and is adapted topermit, by means of a transporting air jet produced by it, the receptionof a second loop 10 of the thread into the storing shalt II. Ifnecessary also the end 11' of the shaft ll may be connected to a suctiondevice which may be intermittently actuated. The leading run of the loop10 moves via a guide 12 to the main noule l3 which has its exit openingsituated before the weaving shed and is adapted to insertintermittently, that is at each revolution of the main shaft of theweaving machine, a length of the thread 1 into the weaving shed, saidlength being measured corresponding to the desired cloth width. Thethread leaving the main nozzle 13 passes a second thread clamp 14 and acutting device 15. The last mentioned device may be of any desired type,and may consist of a movable part 15' and a stationary part 17.Particularly when handling synthetic threads a cutting device may beused which operates by burning or melting the thread by means of heat.

In the embodiment shown the storing shafts 11 and 7 are axially alignedand at the transition between such shafts a screen 16 has been placed inorder that the opposite air streams prevailing in the shafts may notinfluence each other.

The operation of the mechanism described above is as follows.

The drawing shows the mechanism in a phase in which the main noule 13 isabout to insert the loop 10 (formed in the storing shaft 11) into theweaving shed via the thread clamp 14 (open at this moment), and via theinoperative cutting device 15. The thread clamp 8 is in closed positionat this moment whereas the auxiliary nozzle 9 is not actuated.

At the end of the launching by the main nozzle I3 of the thread lengthcorresponding to the loop 10 into the weaving shed, the thread clamp 14is closed, controlled by a shaft 18 driven from the main shaft of theweaving machine, and the cutting device 15, which maybe similarlycontrolled by the shaft 18, is actuated to separate the weft threadlength from the rest of the thread and to permit the beating up of saidlength into the cloth 19 during the second half of the weaving cycle bymeans of the reed 20. At the same time the auxiliary nozzle 9 isactuated by the opening of an air supply valve 21 controlled by theshaft 18, and the thread clamp 8, which is controlled like the clamp 14,is opened in order to transmit the loop 6 (formed during the launchingthat has just ended, by means of the continuously blowing" auxiliarynozzle 5, in the storing shaft 7) into the storing shaft 1 1. Thereafterthe thread clamp 8 is again closed and the actuation of the auxiliarynozzle 9 is ended in order that the thread length formed in the shafi 11may be inserted, with the thread clamp 14 opened, into the weaving shedby means of the main nozzle 13.

We claim:

I. A wei't drawing device for presenting measured thread lengths to aweaving machine, comprising a continuously activated first auxiliarynozzle, mechanism for feeding a thread continuously to such nozzle, afirst storage shalt arranged to receive a first loop of the threaddischarged by such nozzle, a second auxiliary nozzle arranged towithdraw the leading run of such loop of thread from the first storageshalt, a first thread clamp located adjacent to the second auxiliarynozzle, a second storage shaft arranged to receive a second loop of thethread discharged by the second auxiliary nozzle, a main weftinsertingblowing nozzle arranged to withdraw the leading run of the second loopof thread from the second storage shaft, and a second thread clamp and acutting device through which clamp may be closed while the secondauxiliary nozzle is active and the main blowing nozzle is inactive.

2. A weft drawing device according to claim 1 wherein the first andsecond storage shafts are so arranged that the leading run of the loopin the first storage shafi is in alignment with the trailing run of theloop in the second storage shaft.

1. A weft drawing device for presenting measured thread lengths to aweaving machine, comprising a continuously activated first auxiliarynozzle, mechanism for feeding a thread continuously to such nozzle, afirst storage shaft arranged to receive a first loop of the threaddischarged by such nozzle, a second auxiliary nozzle arranged towithdraw the leading run of such loop of thread from the first storageshaft, a first thread clamp located adjacent to the second auxiliarynozzle, a second storage shaft arranged to receive a second loop of thethread discharged by the second auxiliary nozzle, a main weft-insertingblowing nozzle arranged to withdraw the leading run of the second loopof thread from the second storage shaft, and a second thread clamp and acutting device through which the thread passes as it leaves the mainblowing nozzle, whereby during the first half of a weaving cycle thefirst thread clamp may be closed and the second thread clamp may be openwhile the second auxiliary nozzle is inactive and the main blowingnozzle is active, and whereas at the end of the first half cycle thecutting device may be operated to cut off the inserted length of thread,and then during the second half cycle the first thread clamp may be openand the second thread clamp may be closed while the second auxiliarynozzle is active and the main blowing nozzle is inactive.
 2. A weftdrawing device according to claim 1 wherein the first and second storageshafts are so arranged that the leading run of the loop in the firststorage shaft is in alignment with the trailing run of the loop in thesecond storage shaft.